1. Field of the Invention
The present invention relates to a cell. More particularly, the present invention relates to a fuel cell apparatus.
2. Description of Related Art
The fuel cell, advantageous in high efficiency, low noise, and pollution free, has become an energy technology in conformity with the trend of this era. The fuel cell has various types, including a proton exchange membrane fuel cell (PEMFC) and a direct methanol fuel cell (DMFC) which are commonly seen in the market. For example, the fuel cell module of the DMFC includes a proton exchange membrane and a cathode and an anode respectively disposed at two sides of the exchange membrane.
The DMFC uses methanol solution as the fuel, and the reaction formulas of the DMFC are given as follows:Anode: CH3OH+H2O→CO2+6H++6e−Cathode: 3/2O2+6H++6e−→3H2OGeneral reaction: CH3OH+3/2O2→CO2+2H2O
It can be seen from the above reaction formulas, enough oxygen (O2) must be supplied to the cathode during the reactions of the DMFC. Moreover, the higher the temperature of reaction is, the higher the reaction efficiency is.
FIG. 1 is a schematic view of a conventional fuel cell apparatus. Referring to FIG. 1, the conventional fuel cell apparatus 100 includes a fan 110 and a fuel cell module 120. The fan 110 is used to generate an airflow 50 to the fuel cell module 120 so as to supply the oxygen required by the cathode reaction. Moreover, a heat energy Q is generated during the reaction of the fuel cell module 120. If the temperature of the airflow 50 before flowing into the fuel cell module 120 is TA, the temperature of the airflow 50 after flowing through the fuel cell module 120 rises up to TB, where TB-TA is in direct proportion to Q.
However, since the temperature of the airflow 50 produced by the fan 110 is lower than that of the fuel cell module 120, when the airflow 50 flows to the fuel cell module 120, the temperature of the fuel cell module 120 is decreased. As such, the reaction efficiency of the fuel cell module 120 decreases, which further reduce the performance of the fuel cell apparatus 100. Moreover, since the lift of the fan 110 is low, the airflow 50 does not easily take the water produced in the cathode reaction away from the fuel cell module 120. Therefore, the water produced in the cathode reaction is usually vaporized into water vapor first, and then departs from the fuel cell module 120 with the airflow 50. However, the airflow 50 having a low temperature has a low saturated water vapor pressure, making it difficult to vaporize water.
Moreover, the water vapor of the conventional fuel cell apparatus 100 is discharged to the outside, thus the water cannot be recycled. Moreover, since the airflow 50 produced by the fan 110 has a lower temperature, the water vapor is liable to be condensed on the surface of the cathode of the fuel cell module 120, thus obstructing the flow field. Therefore, the oxygen is not supplied to the cathode easily, and the performance of the fuel cell apparatus 100 is thus deteriorated.